The present invention concerns a contact device, more precisely a contact device to which at least one optical fibre is led. The invention also concerns the use of such a contact device.
GB-A-2 178 919 shows a system with a network for distributing wide band signals via optical fibres. The network is particularly suited to transmit digital video signals to TV-apparatuses. The signals are led via optical fibres to a receiver/transmitter unit positioned in a TV-receiver. The signals are thus led in an optical manner all the way to the TV-apparatus.
U.S. Pat. No. 4,555,810 describes a device for the distribution of optical signals. The optical signals are led to optical wall contacts. Thereafter a conversion of the optical signals from the optical wall contacts takes place. The converter may either form a part of an apparatus, for example a TV-apparatus, or may form a part of a separate unit that is plugged into the wall contact.
EP-A-7 537 774 describes a wall socket with both electrical conductors for supply voltage and optical fibres. The wall socket is primarily intended for the purpose that the apparatus that is supplied with the supply voltage from the socket should also be able to communicate with the help of optical signals. The wall socket also comprises one or more optoelectric converters. The wall socket comprises an optical contact member that may co-operate with a corresponding optical plug. The wall socket is primarily intended to receive optical signals from an apparatus in the room and to convert these signals to electrical signals and vice versa, i.e. to convert electrical signals to optical signals and to transmit these optical signals to an apparatus in the room.
The systems that are described in the first two documents above have the disadvantage that it is necessary to arrange optoelectric converters outside of the contact device itself, either in the apparatus to which the optical signals are led or in a separate converter that is plugged into a wall socket.
An optical contact of the kind that is described in the last described document above has several disadvantages. Such an optical contact requires a relatively complicated plug with which the contact co-operates, since otherwise losses in the optical transmission between the wall socket and the plug may easily occur. Furthermore, most apparatuses that are used in a home or in an office are constructed to communicate with the help of electrical signals, which means that the need for such an optical line to an apparatus is limited.
There is an increased need for fast communication with the help of signals that are led via optical fibres. It is therefore more and more common that optical fibres are drawn to a flat or to another part of a building. The apparatuses that communicate with the help of signals that are sent via optical fibres normally require a conversion of the optical signals to electrical signals. This conversion may either take place in the apparatus itself, which requires an optical line to the apparatus, or in a separate optoelectric converter. Such a converter also requires its own current supply, which may be arranged in that the converter is powered by a battery or in that a separate line for the current supply is drawn to the converter. Furthermore, such a separate converter requires space and is often in the way when cleaning or the like is performed when it is positioned in a room, for example lying on the floor. Such a separate converter may also easily be damaged if it lies unprotected. Faults may also occur along the optical transmission that is the case in for example a flat, since the optical transmission is relatively sensible to for example dirt or other influences. Furthermore, the light from the optical fibres may be harmful if for example a child has access to the optical fibres and may direct the light towards an eye.
A further problem with prior technology is that the supplier that has the responsibility for the optical connection to a flat or other part of a building is not always responsible for damages on the connection that takes place in the flat itself or within an office.